fix(api): report tenant-scoped role in tenant users list

A user who is admin in one tenant but member in another must read
'admin' for this tenant — use roleForTenant() rather than the global
u.role fallback when building the tenant users list.

services/platform-api/src/tenants/tenants.service.ts

@@ -14,7 +14,7 @@ import { PricesService } from '../prices/prices.service.js'
 import type { PriceCurrency, PriceCycle, PriceDocument } from '../schemas/price.schema.js'
 import { Subscription, SubscriptionDocument } from '../schemas/subscription.schema.js'
 import { Tenant, TenantDocument } from '../schemas/tenant.schema.js'
-import { User, UserDocument } from '../schemas/user.schema.js'
+import { User, UserDocument, roleForTenant } from '../schemas/user.schema.js'
 import type { PartnerUpdateTenantDto } from '../me/dto/partner-update-tenant.dto.js'
 import type { CreateTenantDto } from './dto/create-tenant.dto.js'
 import type { UpdateBillingInfoDto } from './dto/update-billing-info.dto.js'
@@ -341,7 +341,15 @@ export class TenantsService {
             enrolled = false
           }
         }
-        return { id: String(u._id), name: u.name, email: u.email, role: u.role, enrolled }
+        // Tenant-scoped role, not the global fallback — a user who is admin
+        // here but member elsewhere must read 'admin' in this list.
+        return {
+          id: String(u._id),
+          name: u.name,
+          email: u.email,
+          role: roleForTenant(u, tenant._id),
+          enrolled,
+        }
       }),
     )
     return {